Steelyard



T. PAIRBANKS.

STEELYARB.

No. 4,761. Patented Sept. 15'. l1846l JF-g . 1 NV PETERS,Pholo-Liihngmphsr, Washmgtum D. C.

UNITED STATES PATENT OFFICE.

THADDEUS FIRBANKS, OF ST. .IOHNSBURY, VERMONT.

STEELYARD.

Specification of Letters Patent No.

To all whom t may concern Be it known that I, THADDEUs FAIRBANKS, of St.Johnsbury, in the county of Caledonia and State of Vermont, haveinvented a new and useful Improvement in Steelyards or Apparatus forWeighing Heavy Bodies; and I do hereby declare that the nature of thesar'ne.is fully set forth and represented in the following specificationandV accompanying drawings, letters, figures, and references thereof.

Of the said drawings, Figure 1 exhibits a top view or plan of asteelyard or scale beam, having my improvement applied to it. Fig. 2 isa front elevat-ion and Fig. 3 is a transverse and vertical section of ittaken centrally through the movable weight which slides to and fro uponthe graduated arm.

In the said drawings, A denotes a steelyard lever or scale beam havinggraduations or divisions upon its front face. The said beam` rests andplays upon a fulcum B, and has the scale hung or attached to it in theusual manner. The said scale beam has a movable or adjustable weight Cplaced upon it and adapted to it, so as to rest upon and project belowits top edge both in front and rear, as seen in the drawings. To thefront side and upper part of the weight, I joint a small bent lever orindex pointer D, having its upper arm disposed in a horizontal positionand perpendicularly to the front face of the weight, and its lower armextending downward, so as to engage with a series of shoulders orprojections a, a, a, etc., made upon the front face of the graduated armof the steelyard, there being one of said shoulders to each division ofthe lever, and the same being arranged over the said division as seen inFig. 2.

The shoulders should be so disposed with respect to their respectivedivisions that on movingthe lower arm of the index lever against any oneof the shoulders, the weight C will be brought into its proper positionto balance the weight indicated by the division to which said shoulderbelongs.

The weightis made to extend below and underneath the scale beam, as seenin Fig. 3. To the front face of the part of it which so extends belowand underneath the scale beam, I attach a short graduated scale E, uponthe upper edge of which, I place a 4,761, dated September 15, 1846.

small saddle or carriage Gr having a weight H, suspended from it. Theupper edge of the scale E over the divisions of the scale, is suitablynotched, so as to receive a small index pointer or projection bextending downward from the carriage G, as seen in Fig. 2, and for thepurpose of indicating the division upon the scale which represents thefractional part of a ton, or any other assumed weight, denoted by eachof the divisions of the scale beam to represent eveny tons, hundredweights or pounds, those on the small scale E should be arranged so asto indicate fractional parts of one ton, one hundred weight or onepound.

If the body to be weighed contains twentyl tons, twelve hundred andfifty pounds, we move the weight C, along the scale beam until we findthat the index lever B depresses the beam nearly to a horizontal line.This it will do, when it passes beyond the shoulder a of the divisionwhich represents twenty tons. l/Ve then push or slide back the weightuntil the index lever abuts against the said shoulder. We next move thesecondary weight H upon the scale E, until it brings the beam E to ahorizontal position, which it will when the index pointer of it reachesthe notch of the division which represents twelve hundred and fiftypounds.

The scale beam is borne downward by the united pressure of the weights Hand C, and scale E. Therefore, the weight H constitutes a part of thatwhich is always in action upon the scale beam and whenever the weight Cis moved upon the beam, the small weight H should first have its indexpointer adjusted to the Zero or commencement of the scale. On moving iton its scale outward or in a direction away from the tulcrum B, wechange the center of gravity of the whole weight pressing upon the scalebeam, or throw it fart-her from the fulcrum B.

My invention, when applied to a scale beam, of a platform balancerenders it of great value particularly when adapted to weigh very heavymatters, such as coal, and when great dispatch in conducting theweighing operation is desirable, as it renders useless, and completelyobviates the labor of lifting, the large weights or poises, otherwise sofrequently required. It is particularly useful for Weighing cars andtrains of freight on railways.

Illy improvement, and, therefore, that which I Claim, consists in theauxiliary Scale (E) and Weight (H) as combined and operating with themain Weight substantially in the manner and for the purpose as abovespecified.

In testimony whereof, I have hereto set iny signature, this eleventh dayof April 10 A. D. 1846.

THADDEUS FAIRBANKS.

Witnesses:

HIRAM KNAPP, J. I. FAIRBANKS.

